Venezuela’s neighbours are tightening their borders, alarmed by the exodus of hundreds of thousands of desperate refugees fleeing hunger, hyperinflation and a spiralling political crisis.

Brazil and Colombia are sending extra troops to patrol frontier regions where Venezuelans have arrived in record numbers over recent months.

Colombia, which officially took in more than half a million Venezuelans over the last six months of 2017, also plans to make it harder to cross the frontier or stay illegally in Colombia. Brazil said it will shift refugees from regions near the border where social services are badly strained.

The economic crisis and food shortages which have driven so many from their homes show no signs of easing.

The International Monetary Fund forecasts hyperinflation in Venezuela will hit 13,000% this year, so most salaries are now worth the equivalent of just a few British pounds a month.

All but the very wealthiest, or those with access to support from abroad, are struggling to find or pay for food. Looting to eat is on the rise, with reports of people stoning a cow to death, butchering horses from a veterinary institute and raiding a fishing boat for sardines.

Filippo Martínez, a 45 year-old university researcher reckons he is among the top 5% of Venezuelans, even though he works 17-hour days on two jobs.

“Even people like me in stable and professional [jobs] can’t afford the basics,” he told the Guardian. His monthly salary for working 8am to 5pm at the university now covers just a week’s worth of food, so he works until 1am as a freelance consultant just to survive.

Friends have scattered across the region, and students leave as soon as they graduate. Martínez has stayed only because he spent years working for his current position, and can hardly bear to think about abandoning it.

“I don’t want to be an immigrant,” he says. “There’s a lot of people quitting the country with no plans, no money and no profession.”

Over the last half of 2017, the number of Venezuelans moving to Colombia jumped by 62% to about 550,000, according to immigration officials. But with illegal migration included, officials believe more than 1 million Venezuelans have moved to Colombia since the economic crisis took hold in 2015.

“Colombia has never before experienced a situation like this,” President Juan Manuel Santos said during a visit to Cúcuta, a border city of 670,000 that is the main receiving center for Venezuelan migrants.

“I want to repeat to President Maduro: this is the result of your policies. It is not the fault of Colombians and it’s the result of your refusal to receive humanitarian aid, which has been offered, not just from Colombia but from the international community.”

It was a message echoed by Brazil’s defence minister, Raul Jungmann, who also visited a border town to unveil his government’s new plans.

“This is a humanitarian drama. The Venezuelans are being expelled from their country by hunger and the lack of jobs and medicine,” he told reporters in Boa Vista. “We are here to bring help and to strengthen the border.”

Life in exile is often precarious. In Cúcuta, tired and hungry Venezuelans often sell their possessions, including wedding rings and even their hair, to buy food. Some hole up in temporary shelters or on park benches and rely on soup kitchens set up by churches.

But the flood of departures is unlikely to slow while Venezuelans go hungry at home. “It feels like we are just dying slowly and there’s no hope of change,” said Cristian Sousa, a 24-year-old trainee doctor whose family have almost all left, including his mother, younger brother, an uncle and aunt, and half a dozen cousins.

He has stayed on to finish his degree but is counting the days to graduation. “We used to eat three full-sized meals and fruits, cookies or something between every meal. Now we can barely, really barely, eat twice a day.”

In Colombia, one of the newcomers, Jesús García, said he quit his job as an industrial mechanic with Venezuela’s state oil company in December when his salary no longer covered food for his wife and two kids.

He arrived in Cúcuta last month and while he looks for work, he is busking in a city park, playing a harp and singing folk songs alongside a a fellow Venezuelan, who strums guitar. Bystanders toss the equivalent of about £8 ($11) a day into an open guitar case – which is more than García earned as an oil worker back in Venezuela.